Alkenyl group-containing organo(poly)siloxanes have already been disclosed. For example, DE-B-1 023 463 (Union Carbide Corp., published Jan. 30, 1958), DE-A-24 55 502 (General Electric Co., published Jul. 3, 1975) and the corresponding U.S. Pat. No. 3,846,464 (issued Nov. 5, 1974) disclose cyclic siloxanes which have a SiC-bonded vinyl group on each silicon atom. Straight-chain methylvinylsiloxanes are described in DE-B-1 011 147 (General Electric Co., published Jun. 27, 1957) and DE-A-1 745 342 (Rhone-Poulenc S. A., published Nov. 18, 1971) and the corresponding U.S. Pat. No. 3,498,945, issued Mar. 3, 1970. In addition, the preparation of vinyl-containing organopolysiloxane resins by hydrolysis of vinyltriacetoxylsilane is disclosed in GB-A-752 371 (Dow Corning Ltd., published Jul. 11, 1956).
Therefore, it is an object of the present invention to provide organo(poly)siloxanes having at least one carbon-carbon multiple bond linked to each silicon atom Another object of the present invention is to provide a process for preparing organo(poly)siloxanes having at least one carbon-carbon multiple bond linked to each silicon atom.